Results 31 to 40 of about 24,339 (257)

Variability of Soft X-ray Spectral Shape in Blazars Observed by ROSAT [PDF]

, 2001
In paper 1 (Cheng et al. 2001) we have shown that the soft X-ray spectra of two types of Seyfert 1 galaxies statistically vary differently with increasing intensity.
Cappi M., Catanese M., Cheng L. P., Chiappeiti L., Fan J. H., Georganopoulos M., Ghisellini G., Giommi P., Jian-Yan Wei, Konigl A., Lin-Peng Cheng,Yong-Heng Zhao, Madejeski G. M., Mukherjee R., Padovani P., Perlman E. S., Romerto G. E., Scarpa R., Villata M., Wagner S. J., Xie G. Z., Xie G. Z.   +20 more
core   +2 more sources

The Nature of Micro-Variability in Blazars

Galaxies, 2021
We present the results of a long-term study designed to investigate the nature of micro-variability in blazars carried out primarily at the Southeastern Association for Research in Astronomy (SARA) observatories.
James R. Webb, Viviana Arroyave, Douglas Laurence, Stephen Revesz, Gopal Bhatta, Hal Hollingsworth, Sarah Dhalla, Emily Howard, Michael Cioffi   +8 more
doaj   +1 more source

A Machine Learning Approach for Predicting Black Hole Mass in Blazars Using Broadband Emission Model Parameters

Universe, 2022
Blazars are observed to emit non-thermal radiation across the entire electromagnetic spectrum from the radio to the very-high-energy γ-ray region. The broadband radiation measured from a blazar is dominated by emission from a relativistic plasma jet ...
Krishna Kumar Singh, Anilkumar Tolamatti, Sandeep Godiyal, Atul Pathania, Kuldeep Kumar Yadav   +4 more
doaj   +1 more source

Blazars and Gamma Ray Bursts [PDF]

, 2006
Blazars and Gamma Ray Bursts (GRBs) are the fastest objects known so far. The radiation we see from these sources originates in a jet of similar aperture angle, and we think it is the result of the conversion of some of the jet kinetic energy into random
Ghisellini, G.
core   +2 more sources

Rapid optical variability of TeV blazars [PDF]

, 2011
In this first systematic attempt to characterise the intranight optical variability (INOV) of TeV detected blazars, we have monitored a well defined set of 9 TeV blazars on total 26 nights during 2004-2010. In this R (or V)-band monitoring programme only
Abdo, Abdo, Abdo, Agudo, Aharonian, Albert, Andruchow, Arti Goyal, Attridge, Atwood, Begelman, Begelman, Bramel, Britzen, Britzen, Carini, Cellone, Cellone, Chen, Chrisphin Karthick, Ciprini, Costamante, Czerny, D. K. Sahu, Dai, de Diego, Edelson, Fabian, Fan, G. C. Anupama, Ghisellini, Ghisellini, Ghisellini, Ghisellini, Giannios, Giroletti, Giroletti, Gopal-Krishna, Gopal-Krishna, Gopal-Krishna, Gopal-Krishna, Gopal-Krishna, Gopal-Krishna, Goyal, Guilbert, Gupta, Hartman, Heidt, Helmboldt, Impiombato, Jang, Jannuzi, Jorstad, Kataoka, Kellermann, Kellermann, Kharb, Kidger, Kovalev, Kovalev, Kovalev, Krawczynski, Krongold, Kundt, Kundt, Li, Lister, Lister, Lister, Lobanov, Marscher, Marscher, Monet, Paul J. Wiita, Perri, Petrucci, Piner, Piner, Pollock, R. Sagar, Rani, Rector, Romero, Romero, S. Joshi, Sagar, Sagar, Sagar, Sagar, Sambruna, Savolainen, Schlegel, Schlickeiser, Spergel, Stalin, Stalin, Stalin, Stetson, Stocke, Stockman, Takalo, Tanihata, Taylor, Treves, Urry, Visvanathan, Véron-Cetty, Wagner, Wagner, Webb, Wehrle, Wills, Xie,   Gopal-Krishna   +113 more
core   +2 more sources

The CLASS blazar survey: testing the blazar sequence [PDF]

Monthly Notices of the Royal Astronomical Society, 2004
We discuss the properties of the sources in the CLASS Blazar survey which aims at the selection of low radio power (P(5GHz)<10^25 W Hz^-1) blazars. We use VLA data from available catalogues and from our own observations to constrain the radio core-dominance of the sample which, together with the flat radio spectral index, is a signature of the ...
Caccianiga, A., Marchã, M. J. M.
openaire   +3 more sources

Near infrared polarimetry of a sample of blazars*

EPJ Web of Conferences, 2013
Polarization variability is one of the most ubiquitous characteristic of blazars. Near infrared (NIR)polarization measurements of blazars are not common, contrary to the optical ones.
Pulido J. A. Acosta, Pereyra A., Agudo I., Agulli I., Carnerero M., Segura N. Castro, Gómez J.L., Jorstad S., Marscher A.   +8 more
doaj   +1 more source

Simultaneous Planck, Swift, and Fermi observations of X-ray and gamma-ray selected blazars [PDF]

, 2012
We present simultaneous Planck, Swift, Fermi, and ground-based data for 105 blazars belonging to three samples with flux limits in the soft X-ray, hard X-ray, and gamma-ray bands.
A. Berdyugin, A. Bonaldi, A. Lasenby, A. Lähteenmäki, A. Readhead, A. Reimer, A. Sajina, A. Sievers, A. Sillanpää, A. Tramacere, A. Zacchei, Abdo, Abdo, Abdo, Abdo, Abdo, Abdo, Abdo, Ackermann, Aharonian, Aliakberov, Aller, Angelakis, Atwood, Avni, B. Partridge, Baars, Barthelmy, Bennett, Bersanelli, Burrows, C. Burigana, C. Leto, C. Monte, C. R. Lawrence, C. Trigilio, Caccianiga, Colafrancesco, Condon, Corbett, Costamante, Cusumano, D. Bastieri, D. Gasparrini, D. J. Thompson, D. N. Burrows, D. Riquelme, D. Tavagnacco, Donnarumma, E. Angelakis, E. Cavazzuti, E. Keihänen, E. Lindfors, E. Nieppola, F. Cuttaia, F. D’Ammando, F. Gargano, F. Giordano, F. Verrecchia, F. Villa, Fiorucci, Fiorucci, Fitzpatrick, Fossati, Fuhrmann, G. Chincarini, G. de Zotti, G. Polenta, G. Tagliaferri, G. Tosti, G. Umana, Gehrels, Ghirlanda, Ghisellini, Ghisellini, Giommi, Giommi, Giommi, Giommi, Giommi, Giommi, Gold, González-Nuevo, Grupe, Górski, H. D. Aller, H. Ungerechts, Hartman, I. Nestoras, Isobe, J. A. Zensus, J. González-Nuevo, J. León-Tavares, J. P. Rachen, J. Richards, J. Saarinen, J. Tammi, J. Wu, K. Nilsson, Kalberla, Komatsu, Kotilainen, Kovalev, L. Bonavera, L. Costamante, L. Fuhrmann, L. Takalo, L. Terenzi, L. Toffolatti, Lamarre, Landt, Landt, Lawrence, Leahy, León-Tavares, León-Tavares, Linford, López-Caniego, López-Caniego, M. Capalbi, M. F. Aller, M. Frailis, M. Giroletti, M. López-Caniego, M. Massardi, M. Mingaliev, M. N. Mazziotta, M. Perri, M. Sandri, M. Stevenson, M. Tornikoski, M. Turunen, Mahony, Mandolesi, Mannucci, Marcha, Massardi, Massardi, Massardi, Massaro, Massaro, Mattox, Mauch, Mennella, Meyer, N. Gehrels, N. Giglietto, N. Lavonen, N. Mandolesi, Nieppola, Nilsson, Nilsson, O. King, P. F. Michelson, P. Giommi, P. Natoli, P. Procopio, P. Savolainen, Padovani, Padovani, Padovani, Padovani, Parijskij, Peel, Perlman, Pian, Planck Collaboration, Planck Collaboration, Planck Collaboration, Planck Collaboration, Planck Collaboration, Planck HFI Core Team, Planck HFI Core Team, Poole, Procopio, R. Reeves, R. Reinthal, Raiteri, Raiteri, Richards, Roming, Rosset, S. Buson, S. Colafrancesco, S. Cutini, S. Galeotta, S. Rainò, S. Ricciardi, Sambruna, Scarpa, Schlegel, Shaw, Shaw, Stickel, Stocke, Stocke, T. J. Pearson, T. P. Krichbaum, Tauber, Teräsranta, Toffolatti, Tramacere, Tucci, Urry, Urry, V. Pavlidou, Vagnetti, Van den Berk, Vercellone, Vermeulen, Villata, Voges, von Montigny, W. Max-Moerbeck, Wright, X. Zhou, Y. Sotnikova, York, Zacchei   +218 more
core   +3 more sources

THE NATURE OF TRANSITION BLAZARS [PDF]

The Astrophysical Journal, 2014
14 pages, 11 Figures, ApJ ...
J. J. Ruan, S. F. Anderson, R. M. Plotkin, W. N. Brandt, T. H. Burnett, A. D. Myers, D. P. Schneider   +6 more
openaire   +3 more sources

The Effect of Blazar Spectral Breaks on the Blazar Contribution to the Extragalactic Gamma-ray Background [PDF]

, 2011
The spectral shapes of the contributions of different classes of unresolved gamma-ray emitters can provide insight into their relative contributions to the extragalactic gamma-ray background (EGB) and the natures of their spectra at GeV energies.
Abazajian, Abdo, Abdo, Abdo, Abdo, Abdo, Abdo, Abdo, Abdo, Ackermann, Atwood, Chiang, Dermer, Fields, Inoue, Inoue, Inoue, Kazanas, Lacki, Makiya, McLaughlin, Mukherjee, Nandikotkur, Narumoto, Nolan, Padovani, Pavlidou, Pavlidou, Sreekumar, Stecker, Stecker, Strong, Tonia M. Venters, Vasiliki Pavlidou, Venters, Venters, Venters   +36 more
core   +3 more sources